It is common for sealing, caulking and adhesive agents or similar paste-like, gel-like or viscous materials to be applied to surfaces or between surfaces by extruding the substance through a nozzle whilst simultaneously moving the nozzle in order to form a bead that extends along the surfaces or edges to be joined or sealed.
There are a wide variety of implements designed to assist in the formation and application of the bead of material. Often the material is supplied in a cartridge which allows, via a trigger mechanism or otherwise, for a user to express the material from the cartridge. Usually the material is expressed through a nozzle to improve the accuracy and evenness of the bead.
The nozzle may be integral to the cartridge, or may be a separate component which is attached to the cartridge after an opening through which to express the material has been created in the cartridge. The cartridge will often have a somewhat cylindrical protrusion with an appropriately sized diameter which can be cut away by a saw or knife to form such an opening when required.
Even with the nozzled implement, it is difficult to control the flow of the viscous material, and therefore the result is an undulating and variable bead. Sometimes the application of the material may be discontinuous along the length of the surface or join.
Often more material than is needed will flow from the nozzle, causing mess and wastage. This not only looks unattractive, but also means that different portions of the bead will have different drying times. In some instances, for example when applying adhesive, the user will have to subsequently wipe over the bead to flatten it into a thin even material layer. This is essential to ensure the integrity of the bond formed.
The shape and consistency (particularly in cross section) of the bead are directly affected by the magnitude of the pressure applied to the cartridge and the speed at which the user moves the nozzle along the surface or join. Typically there is little to assist the user in regulating either of these parameters except for, perhaps, the user's own skill and experience. The response of the implement, especially to variations in pressure, can be unpredictable and/or variable; and this makes it difficult for the user to regulate the flow of the viscous material effectively. In some circumstances the application of a continuous pressure will still result in intermittent bead formation.
It is therefore an object of the current invention to provide an implement which will assist in effectively regulating the flow of a viscous material expressed under pressure from a cartridge and through a nozzle; or at least to provide the public with a useful choice.
It is a further or alternative object of the present invention to provide an implement which will assist a user in the accurate application of an evenly shaped and consistent bead of viscous material along a join, channel or surface; or at least to provide the public with a useful choice.
It is a further or alternative object of the present invention to ameliorate, at least to some degree, the problems identified above; or at least to provide the public with a useful choice.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.